Master key cylinder lock



June 17, 1947. G. E. SWANSON 2 2,422,600

MASTER KEY CYLINDER LOCK Filed Oct. 5, 1945 2 Sheets-Sheet 1 120,; 222.51'

9 yn-IM INVENTOR e 17, 1947- r e. E; swANsoN 2 00 MASTER KEY CYLINDERLOCK Fiied Oct. 5, 1945 2 Sheets-Sheet 2 I INV ENTOR 2 Z V 1 BY M MMPatented June 17, 1947 UNITED STATES PATENT OFFICE MASTER KEY CYLINDERLOCK Gunnar E. Swanson, New Britain, Conn. Application October 5, 1945,Serial No. 620,501

6 Claims.

1 This invention relates to the type of master keyed pin tumblercylinder looks, that is, such locks as are installed in series inhotels, office buildings, factories and other large institutions, whichlocks are so constructed that each lock has its individual key, termedthe service key, that will not unlock any other lock, while selectedgroup may be unlocked by a key, called the master key, and all of thelocks may be unlocked by a single key known as the grand master key.

The object of the invention is the provision of master keyed cylinderlocks of attractive appearance which are so constructed as to affordgreater protection against unauthorized manipulation than is provided bycylinder locks of the type mentioned that are in common use, theconstruction also being such that the locks not only can be normallymanipulated by the service, master and grand master keys but can be setby a special service key to prevent them from being manipulated by thenormal keys.

This object is attained by arranging in the casing and barrel, which isrotatable in the casing, a plurality of radially extending rows oftumbler pins, and in the cylinder, which is rotatable in the barrel, asingle row of radially extending tumbler pins, the divisions of theseveral rows of tumbler pins being such that when the cylinder andbarrel are turned to one position the proper service key can be insertedand the cylinder and barrel turned to manipulate the lock; when thecylinder and barrel are turned to another position the proper master keycan be inserted and the cylinder and barrel turned to manipulatethelock, and when the cylinder and barrel are turned to another positionthe proper grand master key can be inserted and the cylinder and barrelturned to manipulate the lock. For the purpose of illustrating the'inventio three radially disposed rows of tumbler pins are shown, therecould be more if desired, and for brevity the middle row of tumblerswill be considered as in the service key position, the row of tumblerson the right as in the master key position and the row of tumblers onthe left as in the grand master key position.

Fig. 1 of the drawings is a transverse section on dotted line l--l ofFig. 2, with the key omitted, showing the barrel locked to the casing bythe tumblers that are in service position.

Fig. 2 is a longitudinal section on dotted line 2-2 on Fig. 1, with aservice key inserted and the cylinder locked to the barrel and thebarrel unlocked from the casing by that key.

Fig. 3 is a transverse section on dotted line 3-3 on Fig. 4, without thekey, showing the barrel locked to the casing by the tumblers in masterkey position. v V

Fig. 4 is a longitudinal section on dotted line 44 on Fig. 3 with amaster key inserted and the cylinder locked to the barrel and the latterunlocked from the casing by that key.

Fig. 5 is a transverse section, without the key, showing the barrellocked to the casing in grand master key position.

Fig. 6 is a transverse section of the barrel and cylinder, on dottedline 6-6 on Fig. 2, showing the means for limiting the turning of thecylinder in the barrel from master key position to grand master keyposition.

Fig. '7 is a fragmentary side view showing the relation of the barrel,cylinder, and the means provided for permitting the cylinder to have alimited rotary movement in the barrel.

Fig. 8 is a face view of a special duty plate that is secured in thecasing, which plate has means for varying the shape of the key slot.

Fig. 9 is a transverse section on dotted line 9--9 on. Fig. 2 showingthe special duty plate secured in the casing.

Fig. 10 i a detail longitudinal section showing the means for securingthe special duty plate to the casing.

Fig. 11 showsa key blank having a specially shaped cross'section.

Fig. 12 shows a key blank having another crosssectional shape.

Fig. 13 illustrates sections that may be given to the keys. 1

Figs. 14 to 16 inclusive show transverse sections of the lock withmodified arrangements of the tumbler pins, Fig. 14 showing a keyinserted and the cylinder and barrel turned to master key position, Fig.15 showing the cylinder and barrel turned to service key position, thekey being omitted, and Fig. 16 showing the cylinder and barrel turned togrand master position, the key being omitted.

Fig. 17 is a section of an alternate structure in which the barrel isbroached to form the base of the key slot.

Fig. 18 is a section of an alternate structure in which the cylinder islocated eccentrically of the barrel. 7

Fig. 19 is a section illustrating the provision of a secondary barrelabout the cylinder.

movement in the barrel. The casing shown has three rows of tumbler holes23 that extend radially with relation to the axis of the cylinder, themiddle row being in what is herein termed the service position. Thebarrel has three rows of tumbler holes 24 so located that by turning thebarrel they can be aligned with the several rows of casing holes. Thecylinder has a single row of tumbler holes 25 and four recesses 26 solocated that by turning the cylinder they may be aligned with the barrelholes. The inner ends of the cylinder holes open into the key slot 21.In these holes are sectional tumbler pins and in the casing holes aresprings 28 tensioned to press the pins inward.

To allow the cylinder a limited rotary movement in the barrel so thatits row of tumbler holes may be aligned with the different rows ofbarrel holes, and then turn the barrel, the barrel has a slot 29 and thecylinder has a pin 30 that projects into this slot.

Secured in the casing at the front end of the barrel is a plate 3! witha fork 32 that fits into a groove 33 (Fig. 10) in the cylinder andenters part way into the key slot .21. This plate has notches 34-35-36positioned and shaped to allow only keys having correspondingcross-sectional shape to be inserted into the key slot in the cylinder.

In the arrangement above described when the tumbler pins of a lock arealigned in service position, as indicated in Fig. .1, the barrel islocked to the casing by the pins 31 only, and the cylinder is free to beturned in the barrel. 'On the insertion of the correctly bitted servicekey the barrel is unlocked from the casing and the cylinder locked tothe barrel by the pins 38 (Fig. 2) so that the barrel and cylinder canbe turned by the key for throwing the locking bolt. The divisions of thepins or" course will differ so that it will require a different key tounlock each lock of a series.

For unlocking a group of locks by a master key the cylinder is turned tothe right from service position until the cylinder tumblers are alignedin master key position in which position the barrel and casing arelocked together by the pins 39 (Fig. 3). Then when the correctly bittedmaster key i inserted the pins are so positioned as to couple thecylinder and barrel together but free the barrel from the casing (Fig.4)

To release the locks by a properly bitted grand master key the cylinderis turned from service position to the left (Fig. 5). When the properlybitted master key is inserted the cylinder and barrel are unlocked andturned to throw the bolt.

The tumbler pins are divided so that the service key will only set inunlocked position the pins of from the cylinder when in master key orgrand master key position.

The recesses 26, before mentioned, are so corelated with the tumbler pinholes in the casing and barrel as to permit the ends of two rows of pinsto rest therein when one row of pins in the cylinder, barrel and easingare in alignment thus registering a division in the said two rows ofpins at the periphery of the barrel, freeing the cylinder for turningwhen the proper key is inserted under the pins that are aligned.

The employment of a plurality of rows of tumbler pins allows thesections of the pins to be longer and more combinations to be attainedthan when there is only a single row of pins divided for more than onekey with overlapping key combinations and also increases protectionagainst unauthorized unlocking of the locks.

In the modified form illustrated by Figs. 14, 15, 16 there is anadditional tumbler pin section 40 inserted in each hole of the row inthe service position directly under the pin section 4| that is beneaththe spring. These pin sections correspond in length to the pins 42 inthe master key alignment, and the receses 43 in the surface of thecylinder. are equal in width to the distance of two of the .pin holesinthe barrel.

Fig. 14 shows the alignment of the tumbler pins in master key alignment,with a correctly bitted key made from a'special duty key blank (Fig. 12)inserted. 'With the elements in this relation the barrel 45 is free toturn in the casing 36 and the cylinder 44 is locked to the barrel by thepin 41. From this condition the cylinder and barrel may be turned by thekey to service positionand when the key is removed the relation of theelements will be as illustrated by Fig. 15, that is, with the barrellocked to the casing by the pin section 40 and the cylinder 44 free toturn in the barrel to the left.

In this relation none of the regular keys will function as theirrespective pin alignments are out of position for functioning except bya special duty key. On insertion of such a key the cylinder may beturned to the left from the position shown in Fig. 15 to the position asinclicated in Fig. 16. In this position none of the regular keys willfunction as they are barred from an individual lock, the master key willset in unlocked position the pins of a group of locks, and the grandmaster key will set in unlocked position the pins of an entireinstallation. It is obvious, of course, that the divisions of the pinswill be varied .so long as the relation of the pin divisions will allowthe cylinder and barrel to be turned by the proper keys.

The plate 3! that, as stated, obstructs a part of the key slot has anotch 34 which allows a conforming key to be thrust into the cylinderand withdrawn therefrom in one position only, and the key has a notch3i) so that when inserted into the cylinder it can be turned from thatposition, but will be held from removal by the plate until turned backto position of insertion.

The notches 35 and 36 in the plate are so located and shaped that onlykeys of conforming cross-sections can be-thrust into and withdrawnentering the key slot by the plate 3!. Turning the cylinder to the leftfrom the position in Fig. 15 aligns the pins in the. cylinder with thetransferred location of the service key pins in the barrel to grandmaster key position. Owing to the wide recess 43 in the cylinder thisturning of the cylinder doesnot'cause any change of position of thegrand master pins in their transposed position, but a divisionisregistered at the periphery of the cylinder between the pins 41 and M.The lock can now be operated by a specially formed master-key.

Looking out of a group of locks can be similarly accomplished byproviding service, master or grand master keys from the specially madespecial duty key blanks (Fig. '12) by turning the cylinder and barrel toalternate pin alignment positions and removing the key used.

Adding a row of mating pins in service position, as described, insteadof having a single pin as first described, makes possible thefunctioning of twospecialduty keys.

Fig. 17 shows an alternate structure of this lock with the barrelbroached as at 50, 5|, 52 to form varying key bases as the cylinder isturned to the several functioning positions. In this case the plate 31is eliminated.

In the alternate structure shown in Fig. 13 the cylinder 44 isofi-center in the barrel 45 and the barrel broached to form, asindicated by the dotted lines 53 to form the varying top positions ofthe key slot as the cylinder is turned to its several functioningpositions. In this construction the plate 3| (Fig. 8) is eliminated andthere are no pins in the cylinder as the key operates directly on thepins in the barrel.

Fig. 19 shows an alternate structure in which there is a tubular shell54 in which the pin recesses 55 are located instead of in the cylinder.This shell also has one row of holes 56 through which the pins 51 in thecylinder extend and move. These pins in the cylinder have varieddivisions providing additional key control of the cylinder by a fourthkey acting to set the divisions of the pins in alignment on theperiphery of the center cylinder to allow the cylinder to be turned.

The basic features of this look which has but a single key slot permitsof many modifications. The varying service, master and grand master keysmay have many difierent sectional shapes and as these keys operate ondifferent rows of pin alignment, instead of, as in the common locks inwhich the several keys operate on a single row of pins the sections ofwhich must necessarily be very short, the pins may be sectioned toprovide many different changes in each row.

The invention claimed is:

1. A cylinder lock which has a casing, a barrel rotatable in the casing,and a cylinder rotatable in the barrel, said casing having a pluralityof rows of tumbler pins, said barrel having a similar number of rows oftumbler pins, each row of barrel pins being adapted to be aligned witheach row of casing pins, and said cylinder having a single row oftumbler pins adapted to be aligned with each row of barrel pins, saidcylinder also having a single key slot aligned with the cylinder pins.

2. A cylinder lock which has a casing, a barrel rotatable in the casing,and a. cylinder rotatable in the barrel, said casing having a pluralityof rows of tumbler pins, said barrel having a similar number of rows oftumbler pins, each row of barrel pins being adapted to be aligned witheach row of casing pins, and said cylinder having a single row oftumbler pins adapted to be aligned with each row of barrel pins, saidcylinder also having a single key slot aligned with the cylinder pins,and said cylinder also having in its surface rows of recesses adapted toreceive the inner ends of the barrel tumbler pins.

3. A cylinder lock which has a casing, a barrel rotatable in the casing,and a cylinder rotatable in the barrel, said casing having a pluralityof rows of tumbler pins, said barrel having a similar number of rows oftumbler pins, each row of barrel pins being adapted to be aligned witheach row of easing pins, and said cylinder having a single row oftumbler pins adapted to be aligned with each row of barrel pins, saidcylinder also having a single key slot aligned with the cylinder pins,said cylinder also having in its surface rows of recesses spaced apart adistance equal to the distance between the rows of barrel pins andadapted to receive the inner ends of the barrel pins.

4. A cylinder lock which has a casing, a barrel rotatable in the casing,and a cylinder rotatable in the barrel, said casing having a pluralityof rows of tumbler pins, said barrel having a similar number of rows oftumbler pins, each row of barrel pins being adapted to be aligned witheach row of easing pins, and said cylinder having a single row oftumbler pins adapted to be aligned with each row of barrel pins, saidcylinder also having a single key slot aligned with the cylinder pins,and a plate secured in the casing and partly obstructing the key slot,said plate having notches positioned and shaped to allow only keys thatwill register therewith to pass through the plate into the cylinder.

5. A cylinder lock which has a casing, a barrel rotatable in the casing,and a cylinder rotatable in the barrel, said casing having a pluralityof rows of tumbler pins, said barrel having a similar number of rows oftumbler pins, each row of barrel pins being adapted to be aligned witheach row of easing pins, and said cylinder having a single row oftumbler pins adapted to be aligned with each row of barrel pins, and asingle key slot partly in the barrel and partly in the cylinder, andaligned with the cylinder pins.

6. A cylinder lock which has a casing, a barrel rotatable in the casing,a tubular shell rotatable in the barrel, and a cylinder rotatable insaid shell, said casing having a plurality of rows of tumbler pins, saidbarrel having a similar number of rows of tumbler pins, each row ofbarrel pins being adapted to be aligned with each row of easing pins,and said cylinder having a single row of tumbler pins adapted to bealigned with each row of barrel pins, said cylinder also having a singlekey slot aligned with the cylinder pins, and said shell having in itssurface rows of recesses adapted to receive the inner ends of the barreltumbler pins, and a row of perforations aligned with the key slot.

GUNNAR E. SWANSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,069,734 Shaw Aug. 12, 19132,113,007 Swanson Apr. 5, 1938

